Notepad++ does not run the javascript. It is just used for editing it. Normally, a browser (or some other javascript engine) will run the code. In my experience, you usually do not load a .js file directly in your browser and expect it to run… normally, you build an HTML file which calls the javascript in some way. Perhaps you should try to create that HTML, and launch that HTML in your browser. (The results will be in the browser, of course, not in Notepad++.)
If I have not answered your question to your satisfaction, maybe you could better explain what exactly you want done, and why it is something that Notepad++ (which is a text editor, not a js-engine or browser) should perform for you.